Department of Psychosocial Science, Faculty of Psychology, University of Bergen, Norway; Department of Health Promotion, Norwegian Institute of Public Health, Bergen, Norway; Haukeland University Hospital, Bjørgvin District Psychiatric Center, Bergen, Norway.
Department of Research and Development, St. Olavs University Hospital, Trondheim, Norway; Department of Mental Health, Norwegian University of Science and Technology, Trondheim, Norway.
Sleep Med. 2022 Jan;89:132-140. doi: 10.1016/j.sleep.2021.12.006. Epub 2021 Dec 17.
To explore associations between intraindividual variability (IIV) in sleep patterns and sleep problems, lifestyle factors, and mental and physical health in individuals with chronic insomnia.
Cross-sectional study of 1720 adults with chronic insomnia (67.8% female, mean age = 44.5) who completed online self-report questionnaires and kept a sleep diary (for at least 10 out of 14 days). Linear regression analyses examined IIV in sleep patterns as independent variables, and sleep problems, lifestyle factors, and mental and physical health outcomes as dependent variables. Analysis of each sleep variable was separately adjusted for the mean value of the corresponding variable and for selected background factors.
IIV in sleep variables was significantly and positively associated with scores on the Insomnia Severity Index (ISI), dysfunctional beliefs and attitudes about sleep (DBAS-16), the Chalder Fatigue Scale (CFQ), body mass index (BMI) and alcohol consumption (AUDIT-C) at study entry. The association between IIV and mental health outcomes (ie the Hospital Anxiety and Depression Scale [HADS] and subjectively reported mental health status [SF-12 Mental health]) were not significant. IIV was associated with higher (ie more positively rated) mean level of sleep quality.
IIV of sleep patterns may be a useful construct for understanding subjective experiences of sleep problems, fatigue and health in people with chronic insomnia. Our findings support notions suggesting that IIV offers additional insights beyond those offered by studying mean values alone; however, discordant findings regarding sleep quality highlight the need for further studies to examine the consequences of IIV.
探讨慢性失眠患者睡眠模式的个体内变异性（IIV）与睡眠问题、生活方式因素以及心理和身体健康之间的关联。
这是一项横断面研究，共纳入 1720 名慢性失眠患者（67.8%为女性，平均年龄为 44.5 岁），他们完成了在线自我报告问卷并记录了睡眠日记（至少 14 天中的 10 天）。线性回归分析将睡眠模式的 IIV 作为自变量，睡眠问题、生活方式因素以及心理和身体健康结果作为因变量进行检验。对每种睡眠变量的分析分别针对相应变量的平均值以及选定的背景因素进行了调整。
睡眠变量的 IIV 与研究开始时的失眠严重程度指数（ISI）、睡眠障碍信念和态度量表（DBAS-16）、Chalder 疲劳量表（CFQ）、体质指数（BMI）和酒精摄入量（AUDIT-C）的评分呈显著正相关。IIV 与心理健康结果（即医院焦虑和抑郁量表[HADS]和主观报告的心理健康状况[SF-12 心理健康]）之间的关联不显著。IIV 与较高的（即评价较高的）平均睡眠质量水平相关。
睡眠模式的 IIV 可能是理解慢性失眠患者睡眠问题、疲劳和健康的主观体验的有用结构。我们的研究结果支持了这样一种观点，即与单独研究平均值相比，IIV 提供了额外的见解；然而，关于睡眠质量的不一致发现强调需要进一步研究来检验 IIV 的后果。
